Muffler with extended chamber



June 25, 1968 L. J, KELSO MUFFLER WITH EXTENDED CHAMBER Filed July 18. 1966 INVENTOR. lcd /fdzs'o rwm/Z/:f

United States Patent O 3,389,764 MUFFLER WITH EXTENDED CHAMBER Leo J. Kelso, Michigan Center, Mich., assigner to Walker Manufacturing Company, Racine, Wis., a corporation of Delaware Filed July 18, 1966, Ser. No. 565,828 3 Claims. (Cl. 181-48) ABSTRACT F THE DISCLOSURE An exhaust gas muler hasr a shell that extends around the inlet tube outside of the housing and acts with perforations in the tubey to form a silencing chamber outside the housing. The shell extends to and is connected to an internal partition and has reduced ends that serve as bushings for attachment to other conduits.

My invention relates to exhaust mufilers for internal combustion engines.

It is an object of my invention to increase the total silen-cing effect of an exhaust gas muflier and also to improve the strength of one of the end headers against blowout.

My invention accomplishes the foregoing and other objects by means of a construction in which one of the small sized spit chambers is mounted on the gas flow conduit to extend out of the muie-r proper and thus through one of the end headers of the muflier. This reduces the unsupported length of the end header and therefore increases its strength and resistance to blowout. The spit chamber so arranged increases total silencing capabilities of the muffler by providing an additional chamber for silencing high frequency sound and roughness. e

My invention is illustrated in the accompanying drawings in which:

FIGURE l is a longitudinal cross section through a typical exhaust gas mufer embodying the invention;

FIGURE 2 is an enlarged cross section along the line 2-2 of FIGURE 1, and

FIGURE 3 is an enlarged cross section `along the line 3--3 of FIGURE 1.

The mufer 1 has a shell 3 which may be insulated by means of an asbestos and outer metal wrap as indicated in the drawings. The inlet end of the muffler is closed by a header 5 and the outlet end by a header 7, both of which are inte-rlocked in a reversely bent or rolled joint 9 with the en'ds of the housing or shell 3.

Inside of the shell 3 and spot welded to the inner layer of metal forming the shell are the transverse partitions 1.1, 13 and 15 which divide the interior of the shell into chambers 17, 19, 21 and 23. The inlet header 5 has an outwardly extending 'flange 29 through which extends and to which is spot welded the housing 31 of a spit chamber unit 33. The housing 31 is necked down at its inlet end 35 to provide an inlet bushing for the muffler and its outlet end is necked down as seen at 37. The section 37 is supported in a fiange 39 in partition 11 and in turn supports the inlet end of a gas flow tube 41 as well as the downstream or outlet end of a gas ow tube 43 which extends within the housing 31 having its inlet end supported in the bushing 35. They gas ow tube 41 empties into the chamber 23 and gas from this chamber flows through an intermediate tube 45, that is supported in flanges in partitions 15 and 13, to reach chamber 19. From chamber 19 the gasflows through 3,3%,761 Patented June 25, 1968 ICB an outlet tube 47 which is supported in the partitions 13 and 15 as well as in the outlet bushing 49 formed in the outlet headerf47. The tubes 41, 45, and 47 are all louvered in the chamber 21 but the louvers in the tube 41 are surrounded by a plural spit chamber housing 51 which acts to attenuate relatively high frequencies in roughness in the gas. The other tubes, 45 and 47 open through their louvers directly into the chamber 21 which acts to attenuate somewhat lower frequencies than the spit chamber 51.

The chamber 19 is connected by means of a'tuning tube 53 to the chamber 17 which therefore acts as a Helmholtz resonator tuned to remove a low frequency note in gas.

The tube 43 inside the housing 31 is also provided with a substantial perforated or open area by means of louvers 54 which open into the closed -chamber 55 that is formed between the tube 43 and housing 31. This chamber therefore acts to eliminate frequencies that are relatively high' but still somewhat lower than those removed by the smaller spit chambers 51. It will be noted that a substantial part of the length of the `housing 31 projects beyond the inlet header 5, thus reducing the unsupported radial length of the header as compared with previous center inlet designs wherein the header would extend inwardly to a tube corresponding to tube 43. Thus the strength of the header 5 isincreased, particularly its resistance to blowout. At the same time the size of the chamber 55 is not limited by thespacing of the partitions inside of the shell 3 thus enabling it to be selected to suit a particular range of frequencies that it is desired to attenuate. At the saine time the small size of the housing 31 as compared with that of the housing 3 insures that it will not interfere with other structure beneath the automobile where the muflier is to be mounted.

Modifications may be made without departing from the spirit and scope of the invention.

I claim:

1. An exhaust gas mufller comprising an elongated housing having an internal transverse partition, headers closing opposite ends of the housing, gas silencing means within the housing, an inlet tube extending through one of the headers and an outlet tube extending through the other of the headers, a shell surrounding one of said tubes and extending through and secured to the header around the tube, said shell extending to and supported in said partition and lhaving a closed end outside of the housing except for said tube, said tube being perforated in the portion thereof inside of said shell, the space between said shell and said tube comprisinga chamber for attenuating sound in the gas passing through said tube.

2. A mufiler as set forth in claim 1 wherein the shell has a reduced end located outside of said housing to form an inlet bushing to receive a gas conveying conduit.

3. A muffler as set forth in claim 1 wherein the shell has a ,reduced end inside said housing to 4form a bushing to receive a conduit forming a part of said gas silencing means.

References Cited 809,206 12/1936 France.

53,320 10/ 1942 Netherlands.

ROBERT S. WARD. JR., Primary Examiner. 

